An inkjet printing system, as one embodiment of a fluid ejection system, may include a printhead, an ink supply that provides liquid ink to the printhead, and an electronic controller that controls the printhead. The printhead, as one embodiment of a fluid ejection device, ejects ink drops through a plurality of orifices or nozzles. The ink is projected toward a print medium, such as a sheet of paper, to print an image onto the print medium. The nozzles are typically arranged in one or more arrays, such that properly sequenced ejection of ink from the nozzles causes characters or other images to be printed on the print medium as the printhead and the print medium are moved relative to each other.
In a typical thermal inkjet printing system, the printhead ejects ink drops through nozzles by rapidly heating small volumes of ink located in vaporization chambers. The ink is heated with small electric heaters, such as thin film resistors referred to herein as firing resistors. Heating the ink causes the ink to vaporize and be ejected through the nozzles.
To eject one drop of ink, the electronic controller that controls the printhead activates an electrical current from a power supply external to the printhead. The electrical current is passed through a selected firing resistor to heat the ink in a corresponding selected vaporization chamber and eject the ink through a corresponding nozzle. Known drop generators include a firing resistor, a corresponding vaporization chamber, and a corresponding nozzle.
In fluid ejection device it is desirable to have several characteristics of each print cartridge easily identifiable by a controller. Ideally the identification information should be supplied directly by the print cartridge. The “identification information” provides information to the controller to adjust the operation of the printer and ensures correct operation.
As the different types of fluid ejection devices and their operating parameters increase, there is a need to provide a greater amount of identification information. At the same time, it is not desirable to add further interconnections to the flex tab circuit or to increase the size of the die to provide such identification information.
For these and other reasons, there is a need for the present invention.